Cereal Chem 53:118 - 125. | VIEW
ARTICLE
New Techniques of Preparation of Improved Sunflower Protein Concentrates.
T. Y. Fan, F. W. Sosulski, and N. W. Hamon. Copyright 1976 by the American Association of Cereal Chemists, Inc.
Countercurrent extractions of sunflower flour with water, acid, or alcohol, and countercurrent diffusion of sunflower seed with acid, were more efficient in solvent use and chlorogenic acid removal than batch extractions with fresh solvents. With five- to six-stage countercurrent procedures, about 90% of the chlorogenic acid was extracted from sunflower flour at a solvent-to-flour ratio of 6:1 (v/w) or from seed at a solvent-to-seed ratio of 3:1 (v/w). The resulting protein concentrates contained over 70% protein and were light in color under alkaline pH conditions. Acid extraction of the flour produced the most soluble protein concentrate, but 40% of the flour solids and 25% of the flour proteins were lost in the liquor or extract. Acid extraction at 80 C or water extraction of protein-denatured flour improved the rate of chlorogenic acid extration, but protein losses in the extract remained high. Aqueous ethanol was an efficient solvent for the removal of chlorogenic acid from the flour, and the protein concentrate yield of 77-78% accounted for 95- 97% of the flour proteins. Acid diffusion of the seed gave intermediate to high yields of protein concentrate with low chlorogenic acid levels. Acid diffusion rates were temperature-dependent and 80 C was required to remove 90% of the chlorogenic acid from sunflower seeds. Important factors in assessing the relative merits of the various processes are the need for recovery of the solvent in the alcohol process, the relative ease in handling of products during acid diffusion of the seed, and the nitrogen solubility of the protein concentrates.